Valve for rock drills



Dec. 15, 1931. w. A. 'SMITH, JR

VALVE FOR ROCK DRILLS Filed June 24, 1929 L a W n E WHHV m & V 7 7/ x MA\\\\ VJ? \\\k fa H KWJ v J F I INVEN TOR. mu MAJ/2013721154 w k HIS A TTORNEY.

Patented Dec. 15, 1931 UNITED STATES BATE-NT O-FFICE WILLIAM A. SMITH, JR OF PHILLIPSBURG RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CQRBOEATION OF NEW JERSEY VALVE r03 neon nnr Ls Application med .Tune 24,

This invention relates to fluid actuated rock drills, but more particularly to a valve adapted for eflecting the distribution of pressure fluid to the ends of the piston chamber.

. One object of the invention is to insure an immediate large supply of pressure fluid to the ends of the'piston chamber at the beginning of the stroke of the piston.

Another object is to insure a rapid action of the valve and thus also to insure'a rapid reciprocatory movement of the piston, V

ther objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating the invention and in which similar reference characters refer to similar parts,

Figure l is a sectional elevation of a portion of the rock drill having the invention applied thereto, and showing the valve in one of its limiting positions, and

Figure 2 is a similar view showing the valve in another limiting position.

Referring more particularly to the drawings, A designates a roclr drill comprising a cylinder B having'a piston chamber C in which is disposed a reciprocatory hammer piston D. The hammer piston D is of a well known type having a forward fluted extension E which in this instance is slidably guided by a front cylinder washer F disposed in the cylinder to form a closure for the front end of the piston chamber C.

In the rearward end of the cylinder B is an enlarged bore G which isadapted to receive rotation mechanism comprising the usual ratchet ring H and the head J of a rifle bar K. The head J carries spring pressed pawls O for engagement with teeth L formed in the ratchet ring H to effect a step by step rotary movement of the piston D; The rifle bar K is provided with suitable flutes P to intcrloclringly engage the piston 'D in a well known manner.

as the ratchet ring and the head J of the rifle bar, are disposed near the extreme outer end of the bore G and in the inner end of the bore G is disposed the pressure fluid distributing mechanism comprising in this instance a 1929. Serial No. 373,332;

chamber R-for' the reception of a distributing valve S. A plate T forms a closure for the' forward end of the valve chamber and also for ghe rearward end of the piston chamber i In the construction shown, the plate T is provided with a hollow extension U which extends rearwardly through the-valve chamber R and (encircles the'rifie bar K for which it forms a guide to prevent the passage of pressure fluid along the rifle bar'into the rearward end of the piston chamber C.

interposed between the rearward end of the valve chest Q and the ratchet ring H are a pair of plates V and W. The plate V forms a seat for the ratchet ring 'H and the'head J of the rifle bar and is in turn seated on the plate ,W which is interposed between the plate V and the rearward end of the valve chest Q.

The valve S, constructed in accordance with thepresent invention, is in the form of a hollow sleeve guided on its exterior surface by the wall forming the valve chamber B. At the rearward end of the valve is a lateral flange X which reciprocates in a pressure chamber Y at the rearward end of the valve chamber and which pressure chamber is vented at its forward end through a passage Z. i A similar vent 6 leads from the rearward end of the pressure chamberY to the atmosphere, and from the same end of the pressure chamber leads a kicker passage 0 which opens with its other end in thepiston chamber C at'a point rearwardly of an exhaust port or ports (Z controlled in this instance by the piston, as is also the kicker passage 0. v r

The valve S is of the hollow type and in the present instance the interior thereof forms areservoir 6 from which the pressure -NEW JERSEY, ASSIGNOR T0 INGERSOLL- fluid'flows to both ends of the piston cham-- her. The pressure fluid flowing to the rearward'end of the piston chamber from the Preferably the rotation mechanism, such groove 9 and the rearward end of the piston chamber C.

In the wall of the valve S and intermediate the ends of the valve are ports adapted to register with an inlet passage 0 which leads to the front end of the piston chamber 0.

Formed within the valve S and in this instance near the forward end thereof is an actuating surface p which is constantly eX- posed to pressure fluid in the reservoir tending to throw the valve S forwardly to a position in which the boss it will extend into the opening 7 to form a closure therefor. Additional means are provided however to augment the pressure acting against the actuating surface p for actuating the valve. To this end an actuating surface q is formed on the rearward end of the flange X against which pressure fluid admitted through the kicker passage 0 may act to assist in throwing the valve forwardly.

At the forward end of the valve S is an actuating surface r against which compression created by the piston D in the rearward ,end of the piston chamber C may act for throwing the valve S rearwardly.

The pressure fluid distributing and rotation mechanisms may be held in the correct operative position in any suitable manner.

.In the present instance this is accomplished by a back head 8 which extends into the rearward end of the bore G and bears against the ratchet ring H. The back head 8 may be clamped firmly in position by the usual spring pressed side bolts (not shown) and in this instance forms a housing for a throttle valve 2? which may be of the hollow rotary type having a port a adapted to register with a passage leading through the back head and opening into a supplyreservoir w also in the back head.

Communication between the supply reservoir w and the reservoir 6 in the valve is afforded in this instance by supply passages a;

in the ratchet ring H and the plate V and by a bore 3 in the plate W. The plate W in the present instance carries a depending extension 2, the outer surface of which cooperates with the bore in the valve to prevent communication between the reservoir 9 and the pressure chamber Y.

The operation of the device is as follows: With the valve S and the piston D in the rearward position illustrated in Figure 1, the

- front end of the valve will lie rearwardly of the groove 9 so that pressure fluid from the reservoir 6 may flow through the opening f, the groove 9 and the inlet passages 9' into the rearward end of the piston chamber 0 to impel the piston D forwardly to deliver its blow against the working implement (not shown).

In this position of the valve the actuating surface p will of course be exposed to pressure fluid tending to throw the valve forwardly. The valve S however will remain in the rear ward position, owing to the pressure fluid flowing through the opening 7 which will then act against the actuating surface 1 and hold the valve rearwardly until the piston D uncovers the kicker passage 0.

After the kicker passage 0 is uncovered, pressure fluid will flow therethrough into the pressure chamber 1 to act against the actuating surfaces 9 to augment the pressure fluid cting against the actuating surface 1) for throwing the valve S forwardly. This movement of the valve will occur immediately after the exhaust port (Z is uncovered by the piston and at about the time the piston strikes against the working implement.

With the valve S in the forward position, pressure fluid will flow from the reservoir 6 through the ports 7; into the inlet passage 0 and thence to the front end of the piston chamber S to drive the piston D rearwardly.

After the piston D overruns the exhaust ports (Z, during the rearward stroke, the air in the rearward end of the piston chamber G will be compressed and this compression will act against the actuating surface 1 to throw the valve rearwardly to its initial position, thus completing the cycle of operations.

I claim:

In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a hammer piston in the piston chamber, a valve chest having a valve chamber, inlet passages leading from the valve chamber to the piston chamber, a valve in the valve chamber having an opening in one end for supplying pressure fluid to one inlet passage, ports in the valve to register with another inlet passage for supplying pressure fluid thereto, a reservoir in the valve from which all pressure fluid is supplied to both inlet passages, an actuating surface on the valve constantly exposed to pressure fluid tending to throw the valve in a forwardly direction, an actuating surface at the rearward end of the valve intermittently exposed to pressure fluid for throwing the valve in the same direction, and an actuating surface at the iron-t end of the valve intermittently exposed to compression in the back endof the piston chamber for throwing the valve rearwardly.

In testimony whereof I have signed this specification. 

